How the WiFi System works in some more detail
For those of you that like to know about the technical detail 
The Marlborough Area Development Trust Community WiFi System allows equipment deployed at the individual premises of the supporting partner businesses/organisations to be ‘aggregated’ into a common community-wide system which is centrally coordinated by the Development Trust.
As shown in the schematic above, where the four sets of coloured circles represent four different premises or general locations, each deployment area has at least one Gateway access point (G) connected to a partner's broadband service (which must be suitable for use for public WiFi). Additional Repeater access points (R) can be deployed that 'mesh' with the Gateway, using radio technology, to extend coverage within larger premises or extended areas, e.g. out into garden areas of pubs etc. Also depending upon the proximity of different premises the access points at individual premises may 'mesh' to create broad area coverage - and this is what happens in (say) the central Marlborough Town area. However each premise can remain as an isolated 'island' simply providing the required coverage across the individual premise location.
The WiFi network, wherever it is accessed, is designated as a ‘public’ network when laptops, smart phones etc., ‘find’ the network, and is called "Free Community WiFi". However when you connect to this WiFi network, access to the Internet is controlled through a special Development Trust portal which uses authentication processes to either let that individual user have access for a short period of time or to enter an access code that allows access for a longer duration.
Access codes are available from the Trust by purchasing a Passport Voucher which is a unique access code that is emailed to you, usually within 24-48 hours, and has a defined validity period of 12 months. The validity period begins when the code is first used and only allows access for the specific device(s) that it is first used with. Once the validity period has expired the user is returned to the WiFi access portal when they next access the service.
Passport Vouchers are provided for convenience to avoid frequent users of the system having to carry out multiple repeat access validations, the Trust offers annual Passport Vouchers to residents, students and anyone that works in the area.
All the Community WiFi information pages:
WiFi Passport Vouchers: click here for details about the annual WiFi Passport Vouchers.